Radioactive Waste Overview High Level Radioactive Waste The U.S. NRC describes high-level radioactive wastes as the highly radioactive materials produced as a byproduct of the reactions that occur inside nuclear reactors. High-level wastes take one of two forms: –Spent (used) reactor fuel when it is accepted for disposal –Waste materials remaining after spent fuel is reprocessed Spent nuclear fuel is used fuel from a reactor that is no longer efficient in creating electricity, because its fission process has slowed. However, it is still thermally hot, highly radioactive, and potentially harmful. Until a permanent disposal repository for spent nuclear fuel is built, licensees must safely store this fuel at their reactors.

Low Level Radioactive Waste Classes of Waste –Class A –Class B –Class C Three existing low level radioactive waste disposal facilities –Barnwell, SC –Hanford, WA –Clive, UT

Low Level Radioactive Waste Waste is disposed in Low Level Disposal Facilities.

Low Level Radioactive Waste Low Level Radioactive Waste is encapsulated either by solidification or placement in High Integrity Containers.

High Level Radioactive Waste

Fuel Rods Filled With Pellets Are Grouped Into Fuel Assemblies

Fuel Assemblies Cool Temporarily in Used Fuel Pools

Dry Fuel Storage at Plant Sites

Temporary Dry Fuel Storage at Power Plant Site

Dry Fuel Storage Projects ENERCON Services has provided engineering services for 18 Dry Fuel Storage Projects throughout the US.

Dry Fuel Storage Projects Dry Fuel Storage Projects include design and engineering for: –Storage Pad –Facility Security –Electrical –Federal Licensing –Local and State Permitting –Cask Heavy Load Lifting

Transportation Containers Are Strong and Safe

Transportation Casks Have Been Tested

Container Loaded on a Truck…

… And Crashed at 80 MPH into a Concrete Wall

Container Broadsided by Locomotive Traveling at 80 MPH

Containers Survived Incineration Tests

Containers Passed Every Test

NRC Concludes Shipping Even Safer Than Previously Thought

At the Repository, Fuel Will Be Transferred to a Special Disposal Container

Yucca Mountain Being Considered As Disposal Site

Seven Miles of Tunnels Built in Yucca Mountain

Yucca Mountain Has Been Thoroughly Investigated

President Recommends Yucca Mountain

New Nuclear Power and Climate Change: Issues and Opportunities Lunch Keynote Presentation William Sweet Senior News Editor IEEE Spectrum

New Nuclear Power and Climate Change: Issues and Opportunities Student Presentation Ashish K Sahu and Sarina J. Ergas University of Massachusetts - Amherst

Perchlorate Reduction in a Packed Bed Bioreactor Using Elemental Sulfur Ashish K Sahu and Sarina J. Ergas

Background Perchlorate (ClO 4 - ) –Stable –Non reactive Trace levels of Perchlorate –Disruption of hormone uptake in thyroid glands

Geographic Contamination No National Standards MCL set by the Commonwealth of Massachusetts (2  g/L) California advisory levels (6  g/L) Other states (NY, NV, AZ, CO, TX) 18  g/L Ref: ewg.org

Sources of Perchlorate Natural –Atmospheric Sources –Chilean nitrate fertilizer Anthropogenic –Missiles, Rockets –Fireworks –Leather Tannery Industries –Fertilizers

Physical Processes Chemical Processes Biological Processes Combination of the above Treatment Processes

Perchlorate Treatment Processes PhysicalDestructive Process Chemical Biological GAC RO/NF Electrodialysis CC-ISEP Bioreactors Hybrid Technologies Bio-remediation Phytoremediation IX Others Others (MBR) CSTR PFR Reducing metals

Outline Biological Perchlorate Reduction Use of Elemental Sulfur Experimental Protocol Results Conclusions

Biological Perchlorate Reduction Principle: Microorganisms convert perchlorate to chloride Heterotrophic microorganisms Use organic carbon as their carbon source Electron donors are methanol, lactate, ethanol, wastewater Autotrophic microorganisms Use inorganic carbon as their carbon source eg: NaHCO 3 Electron donors are S, Fe 0, H 2

Use of Elemental Sulfur 2.87 S H 2 O + ClO CO HCO NH 4 + → 5.69 H SO Cl C 5 H 7 O 2 N Electron Donor: Elemental Sulfur Electron Acceptor: Perchlorate Carbon Source: Bi-carbonate Low biomass production Low nutrient requirements Anoxic conditions Alkalinity destroyed

Advantages of Elemental Sulfur Waste byproduct of oil refineries Excellent packing media Relatively inexpensive and easily available Applications in packed bed reactors and permeable reactive barriers

Objectives –Enrich a culture of Sulfur Utilizing Perchlorate Reducing Bacteria (SUPeRB) –Investigate the use of packed bed bioreactors to treat perchlorate contaminated waters by SUPeRB –Test the bioreactor for varying operating conditions

Batch Culture Enrichments Denitrification zone of Berkshire wastewater treatment plant, Lanesboro, MA 5mg/L ClO 4 -, S o and oyster shell, nutrients in groundwater Analytical Techniques –pH –ClO 4 - concentration using IC (EPA method 314.0)

Batch Culture Enrichment (SUPeRB)

Packed Bed Reactor Reactor inoculated with SUPeRB Media: Elemental Sulfur pellets (4 mm), oyster shell (3:1 v/v) Volume: 1 liter Ports: 5 ports

Packed Bed Reactor Operation Experimental Phase Perchlorate concentration mg/L EBCT hrs Recirculation Ratio Q R /Q S o particle size Phase I Intermittent at (40-1,500) 4 mm Phase II Reactor ,0004 mm Reactor NO 3 - -N (10 mg/L) 8-30None4 mm Reactor None0.85 mm

Bioreactor Performance-Phase II (Effect of Empty Bed Contact Time (hrs))

Bioreactor Performance-Phase II (Effect of Empty Bed Contact Time)

Bioreactor Performance-Phase II (Effect of sulfur size particles)

Bioreactor Performance-Phase II (Effect of Nitrate on Perchlorate Removal)

Summary SUPeRB reduced ClO 4 - from 5 mg/L to <0.5 mg/L in 15 days using S 0 and OS High levels of perchlorate (5-8 mg/L) were successfully reduced to < 0.5 mg/L in the bioreactor at an EBCT of 13 hours Low levels of perchlorate (  g/L) were reduced to < 4  g/L at an EBCT of 8 hours

Summary… Presence of nitrate did not inhibit perchlorate reduction Perchlorate reduction was somewhat independent of media particle size

Applications and Future Work Pilot scale of system for perchlorate remediation Ex-situ remediation In-situ remediation by Permeable Reactive Barriers (PRBs)

Acknowledgements Water Resources Research Center (WRRC), TEI at UMass-Amherst Massachusetts Technology Transfer Center (MTTC) for commercial potential Advisor: Dr. Sarina Ergas Teresa Conneely, Department of Microbiology for FISH and microbiology analysis Tach Chu and Charlie Moe (High School) for culture and bioreactor maintenance